Control for axminster loom tube frame conveyer systems



Sept. 5, 1950 W. H. WAKEFIELD CONTROL FOR AXMINSTER LOOM TUBE FRAME CONVEYER SYSTEMS Filed Dec. 18, 1947 3 Sheets-Sheet 1 mvENToR wALrEn/iwA/(EF/E/.a

ATToR EY Sept. 5, 1950 w. H. WAKEFIELD CONTROL FOR AXMINSTER LOOM TUBE FRAME CONVEYER SYSTEMS 3 Sheets-Sheet 2 Filed Dec.

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INVENTOR WALTER WAKEF/ELD ATTORNEY Sept. 5, 1950 w, H. WAKEFIEL 2,521,430

CONTROL FOR AXMINSTER LOOM TUBE FRAME CONVEYER SYSTEMS Filed D96. 18, 1947 3 Sheets-511661'. 5

FIG.5 l l INVENTOR WALTER HWAKE'F/ ELD am@ W ATTORNEY Patented Sept. 5, 1950 UNITED STATES OFFICE CONTROL FOR AXMINSTER EOM TUBE FRAME CONV EYE-Ri SYSTEMS Walter lll..Wakefield;l i/Vorcester,vv Mass., assignor to Crompton & Knowles LoomWorks, Worcester, Mass., a corporatonof Massachusetts Application December 18, 1947; Serial No. 792,396

(Clf. 139-7 13.(3laims. 1`

This invention. relates to. improvements. in AX- minster' looms' and it isxthe generalv object ofthe invention. to. drive.- the; greater part of the tube frame conveyor systemtbyavariable speed motor.

Axminster looms-ordinarily operate withra conveyor system.- carrying ai large number of tube framesl extending betweenendless chains which are trained around sprocket wheels onfa so-calied pullover shaft". Thisl shaft is given` an angular motion for each tuft forming operation'. of: the loom, andi'when the loom is operating three-shot theL shaft.- moveslv every third pick or weft' laying beat orY theloom.

In some Axm-in-ster loomsy the pullover shaft is able-to move theentire conveyor system, but in Wide loom-s the tubeframe conveyor system is very heavy and it is desirable todrive' a small part only ofthe System by the pullover shaft and drive the greater part of it by a supplementary motor. Under these conditions the' motor must be regulated'to drive its part'of thesystemat the same average' speedA as that at which' the shaft drives its part'. It has been common practice inthe past fewyears to form the'conveyor chains with wellswhich by their-variation in depth open and close switches which stop and' start a con-'- veyor system driving motor. In suchan arrange'- ment, the, motor is idl'e for a period" of. several dozens of picks of the loom and then is active forl a period during which it moves thev conveyor system. at a relatively, high speed; Furthermore, the motor whenstartingpicks. up. its stationary loadlwith. anabruptstart whichstrains the driving parts and! subjectsthem to, considerablev Wear.

It is ari-.important object ofthe` present inventionto drivealarge partof the conveyor system bya motor which runs continuously duringA loom operation but at` a. speed.. which, varies in such manner that. its. average speed will; movev the system. at therate required by the pullover. shaft.

The. conveyor system is composed. of a short tight section. drivenby. the pullover shaft and a longer tight section. drivenby the.- motor.. These sections are connected together by slackportiens forming., Wells. It. a` further object ofV thev in.-

ventionY to.. regulatev the conveyor system motor a, variableresistanceunit one part. of which ismoved, bythe pullover shaft in time withA one of. the tight sections and. theother part of which is moved by the motorV in time with the other tight-section In this Way the controlis derived from the tight sectionsand the Wells which are .undriven partsof. thesystem can; be short and shallow.

The invention can be carried into effect by either-direction alternatingcurrent motors. When adirect. current motor is used the changing; resistanoe:A can bein series wit-hfthe field of ashunt Wound. motor, and.` in thecase of a polyphase alternatingY current motor changing resistances can be in; series with the'windings of a rotor. In either instance the: periodic advance of thexpullover shaft will change the resistance unit to cause the` conveyor system motor to` runY at a higherV than.r average speed, and during the time the. pullover shaft isat rest that part of the aforesaid resistance unit which moves with the conveyor system motor has an opportunity to restore itself: to normal position relatively to: the other part. of the unit. In this Way one; part of the resistance unit advances periodically and. the other part then moves at an increased: rate to catch up` withz the first part.

ft isa. still further object of the` invention to construct the resistance unit so that the'l pull over shaft and 4conveyor system motor can be reversed.

With these and other objects in View which will appearV asA the description proceeds, rnv-invention resides in ther combination and arrangenient. of parts hereinafter described' and set forth.

In the accompanying drawings, wherein two forms of the invention are illustrated Fig'.y l is'a side elevation of an Axminster l'oom and the overhead or tube-frameconveyor system therefor equipped. Withv a direct current shunt woundmotor used with the preferred form ofthe invention,

Fig. 2`isan enlarged side elevation ofthe'y upper left hand" part of Fig'. 1`,

Fig. 3 is a detailed front elevation looking. in the direction of arrow 3; Fig.. 2., and showing the resistance untused with the preferred form of theinventon,

Fig. 4 is a vertical. section on line 4 4', Fig. 3,

Fig. 5 isa diagrammatic View of the, circuit for the shunt Wound direct current motor,

Fig. 6.' is a diagrammatic view showing. several relative positions of the two members of the resistance. unit used. in the preferredv form of the invention,

Figi "l is. a view similar toFig. 3 but showing the form. of'resistance unitused with apolyphase alternating current motor employedv in the-.modied form 'of theinventon,

Fig. 8r is. adetailed verticalsection on line 8.-8, of Fig. 7.,

vzontal shaft 31. number of worms 38 which mesh with and drive one of which is shown at I.

sprockets 56 being shown in Fig. 3.

Fig. 9 is a diagrammatic view of the electric circuits used with the modified form of the invention, and

Fig. 10 is a diagrammatic View showing the relation of the speeds of the two tight sections of the tube frame conveyor system.

Referring particularly to Fig. 1, the loom proper is designated at L and the tube frame conveyor system at CS. The loom is provided with a driving motor LM connected by gearing to a main shaft 2l to which a cam 22 is secured. The latter rocks a levr 23 the upper end of which is pivoted to upper and lower rods 24 and 25, respectively. These rods extend forwardly and are connected to rocking levers 26 and 21, around a pullover shaft P. Each of the levers 25 and 21 is provided with a feed pawl not shown but Well understood, and a control pawl shield lever 28 moved by a hand lever 219 and link 30 determines which of the feed pawls shall be in operative position. When lever 28 is up it disables the pawl of lever 26 and permits the pawl of lever 21 to move to operative position so that upon backward movement of the rods 24 and 25 the shaft P will turn in a counter-clockwise direction as viewed in Fig. l. If lever 28 is down shaft P will turn in a clockwise direction each time the upper part of lever 23 moves rearwardly.

When the loom is Weaving a three shot fabric the shaft P will be advanced every third pick of the loom and ordinarily in a time which is slightly more than half the time of one pick. The shaft then remains at rest until lever 23 moves rearwardly again. The loom also has a lay 3| and tuft cutting mechanism part of which is indicated at 32.

The overhead conveyor system CS is supported lby a framework including an upper horizontal I-beam 36 which supports an elongated hori- The latter is provided with a worm wheels 39, 40, 4l and 42 secured to cross shafts 43, 44, and 46, respectively. Each cross shaft is provided with a pair of sprocket wheels 41 meshing with two endless chains 48 and 49,

one at each side of the loom, which carry tube frames T.

The conveyor system includes two tight sections which are permitted to have a slight amount of independent motion relatively to each other by two loose sections. The upper tight section TS driven by shaft 31 comprises the greater part of the length of the system and eX- tends from shaft 45 to the right, Fig. 1, around idler sprockets 56, up to and over shaft 43, and then to the left over framework 35 to the sprocket 41 on shaft 46.

The other tight section PS is much shorter than the section TS and is driven by the pullover shaft P. The lower parts of section PS extend around sprockets secured on the pullover shaft The upper right hand part of section PS, Fig. 1, meshes with a freely turning sprocket 52 supported on framework 35. The upper left hand part of section PS meshes with a second sprocket 53 secured to a cross shaft 54 rotating freely on framework 35 -independently of shaft 31.

A small chain 55 meshes with sprockets 56 turning with sprockets 52 and 53, one of the Sprockets 52 and 53 therefore turn in unison and in the same direction, and shaft 54 turns with them. These sprockets are turned by a force derived respectively, which move angularly' from pullover shaft P and transmitted by tight section PS. For reasons to be pointed out hereinafter it is important to note that conveyor chain sprocket 53 and shaft 54 turn in timed relation with the pullover shaft P independently of the tight section TS of the conveyor system and shaft 31.

The two tight sections of the conveyor chain system are loosely connected by front and back freely hanging wells WF and WR. The length of these wells is not important, but for brief recurring intervals they should permit movement of the pullover section PS at a rate which is relatively faster than the rate at which the tight section TS moves.

The conveyor chains 48 and 49 progressively move the tube frames T through a transfer station S below the shaft P. When a tube frame, such as T', Fig. l, reaches the transfer station it will be moved :by mechanism not shown down to tuft forming position and then back to the conveyor chains While shaft P is stationary. The latter shaft will then be given an angular movement, which may be 1/6 of a turn, to move the next tube frame to the transfer station.

The matter thus far described is of common construction as shown in prior Patents Nos. 1,512,057 and 1,553,558 and of itself forms no part of the present invention except as noted hereinafter.

In carrying the preferred form of the invention into effect I drive the shaft 31 by a shunt wound direct current motor DM having an arma.- ture A and a eld coil F. The motor runs continuously during loom operation but at a varying speed caused by changes in the strength of the magnetic field. The motor has a built-in gear reducer not shown and is connected to shaft 31 by gearing 51.

The strength of the electric current flowing through field coil F is regulated by a variable resistance speed control unit CU including a drum resistor member 60 and a sweep arm member 6I. Both members are mounted on shaft 54, member 60 being secured to and turning with the shaft and member 6| rotating freely on the shaft.

A drum 62 forming part of member 60 is keyed to shaft 54 and is made of insulating material supporting a series of contact buttons 64 arranged concentrically around shaft 54. Resistance elements 65 are connected to the buttons to be in series and are contained within the drum. Two collector rings 66' and 61 extend peripherally around the. drum and Contact stationary brushes 68 and 69, respectively. Right hand button 64, Fig. 4, is connected electrically to ring 66 while the left button is connected to ring 61. Since the drum resistor member 60 is fast'with respect to sprocket 53 and shaft 54 it is turned by power derived from the pullover shaft P and has an advance movement each time the tight conveyor section PS moves another tube frame to the transfer station.

The sweep arm member 6I comprises a resilient contact arm 10 the free end of which engages the buttons 64. Arm 10 is secured to a disk 1l made of insulating material and having thereon a peripheral collector ring 12 electrically connected to arm 10 and engaging a stationary brush 13. A small sprocket Wheel 14 is secured -to disk 1| and meshes with a tight chain 15 l and 2i', and meshes with the chain 15. Chain. 't5 causes sweep arm 'l0 to turn in timed' relation with thetight conveyor section TS and motor DM.

VIn Fig. 5- which shows the circuits for motor DM power line L is. connected to one side of field coil F through a shipper controlled switch 80 which is closedr during loom operation but open when the loom is not running. Switch 8l in. switch box SB, Fig. l,y is controlled by handle 2.9'. and is connected to the other power line L2. A. reversing switch 82 is connected between lines L and L2 and the armature A and may conveniently be located in box SB under control of handle 29.

In the operation of the matter thus far described it may be assumed that the pullover shaft P is driven in such a direction as to cause counter-clockwise angular motion of resistance member 60, Fig. 1, each time a new tube frame is moved to the transfer station, and that shaft P isstarting to rock clockwise. Switches 80, lll` and 82 will he in their full line positions in Fig. 5 and motor DM will be running at low speed because. sweep arm 'I0 is in such position as to cut out most of ther resistance in circuit with the field coil F. At the start of the turning movementr of shaft P the sweep arm 1U and resistance member will be in what may be considered their normal relation shown in Figs. 4 and 5 and position I of Fig. 6 with the sweep arm moving at itsminimum rate of angular motion. Upon completion of the angular movement of shaft P, which occurs while sweep arm 'I0 is almost at rest or moving very slowly, the resistance member willv have advanced to the dotted line position of Fig. 5 and position II of Fig. 6. A greater amount of resistance will now be in series with the field coil, thereby increasing the speed of motor DM and causing the sweep arm to move to the left at an increased rate.

Position III of Fig. 6 shows the sweep arm continuing to move in a left hand direction while the resistance member remains stationary in its new position. As motion of the sweep arm continues the amount of resistance in series with the field coil diminishes to decrease the speed of motor DM. The sweep arm will continue to move until the parts assume the position shown at position IV in Fig. 6 where the resistance member and sweep arm are back in the same relative position which they had at the start of the operation, as shown in position I, Fig. 6. The speed ofl the motor and the resistance are such that by the time the two members 60 and 6I of the resistance unit. reach the last position described the pullover shaft P will ordinarily have another angular motion and the operation will be repeated. During constant speed running of the loom the arm 10 will sweep over a given group g of buttons which may be considered the normal range of its motion relatively to the resistance.

Fig. 10, which applies to both forms of the invention, indicates graphically the times of op eration of the pullover shaft and its relative speed with respect to the varying speed of the motor DM. The horizontal line fe represents time of the loom and the vertical line fh represents instantaneous speeds of the pullover shaft and motor DM .and the two tight parts PS and TS of the conveyor system. The curve lc represents the vfirst rocking of shaft P starting at the beginning of the rst pick of a three-pick cycle and completed before the end ci' that pick. The

pulloverk shaft and tight section PS then remain idle for the balance of the kthree picks. The line m represents the speed of the motor DM and the tight part TS of the conveyor system which it moves.

At the beginning of the first pick the motor speed will' be low, but as soon as the resistance advances ahead of sweep arm the field current is weakened and the speed of the motor DM increases to aV maximum occurring about at the time curve k falls back to zero. The, resistance member is now at rest and the motor, the sweep arm and section TS move ata rate faster than their average rate but at a rate which decreases as continued running of motor DMy causes the sweep arm to reduce the resistance in series with field coil F. Motor speed will drop. to its. low valuev occurring when the pullover shaftl again rocks as indicated by curve la. The time of operation of motor DM, that is, three picks of the loom, together with its changing rates as it runs, moves the tight section TS the same amount that section PS is moved by the pullover shaft.

The description just given assumes that the loom runs at constantV speed and that the range of' buttons over which arm 'l sweeps is the group g, position Il, Fig. 6. It will be noted that there at least one reserve button on each side of range g.

The amount of resistance will be so chosen as to cause the motor DM to adjust itself to some variation in the speed of the loom and the length of the intervals between successive rockings of shaft P. If, for instance, the length of the intervals between rocking of shaft P should be slightly increased due to slower loom speed sweep arm it will move to the left of its position shown at IV, Fig. 6, and engage one of the reserve buttons Contact with which cuts still more resistance out of the field circuit, thereby causing motor DM to run at a rate below its normal low rate. This allows time for the next rocking of shaft P. Under these conditions the sweeping range of arm 'lil will be shifted to the left of range g.

lf, on the other hand, the length of the intervals between rockings of shaft P should be reduced due to a temporary increase in loom. speed, the resistance will advance before arm 'l0 reaches the left end of range y, and the range of the group of' buttons over which arm l@ sweeps will be shifted to the right of range g, causing faster than normal running of motor DM.

Within limits of loom speed variation the sweep arm will find its correct range of motion with respect to the buttons Gil and the resistance. It will be seen that the shaft P and the resistance member t6 by their periodic angular movements serve as a pacemaker and the sweep arm 10 driven by the motor serves as a follower which always tries to catch up to a given relative position with respect to the resistance member before the latter is again moved.

The foregoing description assumes only one direction of turning of shaft P and motor DM. When handle 29 is moved to reverse the direction of turning of the pullover shaft switches 8l and 82 will shift to the dotted line positions of Fig. 5, and the resistance will be moved to the right of the sweep arm, Figs. 1, 4y and 6, whenever shaft P rocks. The operation already described will be the same except reversed.

At the end of the reversal it will usually be desirable to weave a non-pile heading. This is done by moving handle 29 toits middle or neutral position in which switches 8i and 82 are open and motor DM is idle.

inthe modified form of the invention a polyphase induction motor IM is used having a rotor 90 wound with three coils 9|, 92 and 93, as shown in Fig. 9. Three resistances are provided for the coils and are indicated at R', R2 and R3. When resistance is introduced into the circuits of the windings of a wound rotor the speed of the latter is reduced, this condition being the opposite of that already described for the eld of motor DM. In the modied form, therefore, resistances will be cut out of the rotor coil circuits as the pullover shaft advances.

The small chain 15 and its sprocket Wheels 14, 16 and 11 will be the same as in the preferred form of the invention, and the shaft 54 will have mounted thereon a variable resistance speed control unit 9S comprising a resistance drum member and a sweep arm member |0I, see Figs. 7 and 8.

The drum |00 is secured to shaft 54 and has contact buttons |02 arranged in three groups |03, |04 and |05 connected respectively to the three resistances R', R2 and R3 similar to resistance of member 60. Drum |00 has six peripheral collector rings |05||| arranged in three pairs, and the rings of each pair are connected to the end buttons of the corresponding group 03405, see Fig. 9. The rings |06||| engage brushes ||2l l1, respectively, mounted on a support l I6 made of insulating material.

The sweep arm unit |0| has a disk |20 made of insulating material and having secured thereto three electrically connected sweep arms |2|, |22 and |23. Disk |20 is secured to sprocket wheel 14 and turns in time with the tight section TS.

The wiring for the modified form of the invention is shown in Fig. 9. Main power lines L3, L4 and L5 are connected by switch |25 to wires |26, |21 and |28 which supply power for both the loont motor LM and the motor IM. A switch controlled by shipper mechanism designated generally at |3| is operative when the loom is running to connect wires |26, |21 and |28 to wires |312, 33 and |34, respectively, leading to a reversing switch from which wires |36, |31 and |38 lead to the stator |40 of the motor IM. When the loom is not running switch |30 is open. Switches |42, |43 and |44 are connected by rod |45, under control of handle 29, to the blades of switch |35. These switches are open when lever 28 is in neutral position and shaft P is at rest for the weaving of a non-pile heading. Motor IM can run only when the loom runs and when pile fabric is being woven.

In the operation of the modified form of the invention it may be assumed that the tight sections PS and TS move as first described in connection with the preferred form. At each angular movement of shaft P the resistance member |00 will move counter-clockwise, Fig. 8, while the sweep arms are almost at rest. This motion of member |30 will cut resistance out of the circuits of the coils or windings 5|, 92 and 93, and motor Speed will increase. Member |0| will thereupon move faster due to increased speed of the tight section TS, and eventually catch up with the member |00. The operation is in general the saine as that described for the preferred form of the invention, but switches |132, |43 and |44 are connected to the ends of their resistances away from which the sweep arms #2L |22 and |23 move due to increased motor speed. In the preferred form the opposite condition exists, that is, switch 8| is connected to that end. of the resistance R, see Fig. 5, toward which sweep arm 10 moves.

Reversal of switch |35 causes motor IM to reverse due to reversal of rotation of the field of magnetic force in the stator, and at the same time reverses switches |42, |43 and |44. If the reversal should occur when the members |00 and |0| are in the position suggested in Fig. 9, motor IM would immediately start to run faster and the sweep arms would be moving clockwise when the resistance member was moved in the same direction by the pullover shaft. This same condition would also exist in the preferred form of the invention.

From the foregoing it will be seen that the invention provides means by which the two tight sections of the conveyor system jointly operate a speed control unit for the motor which drives the long conveyor section TS. The pullover shaft sets the pace and determines the average speed or rate of movement of section PS, and the control unit causes the motor DM or IM to drive section TS at the same average rate. 'I'he motor control includes a resistance member and a sweep arm member, one member being operated by a force derived from the pullover shaft and the other being operated by the motor. While in each form of the invention the resistance member has been shown as operated by the pullover shaft and the sweep arm member by the conveyor system motor, I do not wish necessarily to be limited to this particular arrangement for driving the two members of the speed control unit. The slack wells are provided to permit a slight relative motion of the tight sections with respect to each other, but they do not in any way enter into the control of the motor and they can be short and shallow. The pullover shaft when operating' will intermittently feed chain into and lengthen one well while drawing chain from and shortening the other well, and the chain driving motor will draw chain :from the one well and feed chain into the other well, the wells permitting the-chain section TS to be driven at an average speed equal to that of section PS. In the preferred form of the invention the periodic movements of the pullover shaft cut resistance into the circuit of the field coil of the direct current motor to increase speed of the latter and enable the sweep arm to catch up with the resistance member. In the modified form of the invention the reverse relation with respect to motor speed and resistance requires that the pullover shaft when moving reduce the resistance in series with the windings of the rotor. In both forms of the invention the conveyor system motor is temporarily speeded up when the pullover shaft rocks and then gradually diminishes its speed until the pullover shaft again rocks. Provision is also made for reversing the direction of movement of the conveyor system, this part of the invention including two connectors for each resistance and the switch means which allows current to flow through one or the other of the ends of the resistance, depending upon the direction in which the system 1s movlng.

Having thus described my invention it will be seen that changes and modifications may be made therein by those skilled in the art without departing from the spirit and scope of the invention and I do not wish to be limited to the details herein disclosed, but what I claim is:

1. In an Axminster loom provided with a tube frame conveying system having two driven seg-J ascenso tions, pullover mechanism -periodically -inoving -onefof fsai'dsectionsga continuously running motor 'having driving relation with the other section 1only and separate from the "loom, and speed rcontrol means for the motor 'rcintly controlled by said two 0'driven sections causing the motor to drive said othersection .at an average speed equal to the averagespee'd atw'hioh the pullover mechan-ism moves said yonesection.

2. In an Axminster loom provided h aitube frame conveying system having 'two vdriven sections connected by two slack sections, pullover mechanism periodically moving one of said 'driven' .sections Iand lengthening one slack 'section and shortening `the other 'slack section, :a .continuously `running variable 'speed motor separate I`fromfthe ioom driving the other driven section, 'and speed contro-1 means for 'the motor operated jointly by said driven :sections Iand including a Variable resistance causing the motor to -d-rive said other -driven section @to shorten :said one slack section and lengthen said other slack section and drive said other driven section at the same average speed at which the pullover mechanism moves said one driven section.

3. In an Axminster loom provided with a tube frame conveying system having two driven sections, pullover mechanism periodically moving one of said sections, driving means separate from the loom operating continuously during loom operation to move the other section only, and control means for varying the speed of said driving means controlled jointly by said sections and tending to cause the driving means to move said other section at an average speed equal to the average speed at which the pullover mechanism moves said one section.

4. In an Axminster loom having a driving motor and provided with a tube frame conveying system having two driven sections, pullover mechanism operated by the driving motor periodically moving one of said sections, an electric motor separate from the driving motor for the other section driving the latter continuously, and electric speed control means for the electric motor including two rotary members moved by forces derived from the pullover mechanism and electric motor causing the latter to operate at variable speeds to move said other section at the same average speed as that at which the pullover mechanism moves said one section.

5. In an Axminster loom having a tube frame conveying system including a tight section forming part of said system and having periodic movements and a second tight section forming another part of said system, an electric variable speed motor for said second section only continuously driving the latter while the first section moves and is also at rest, and electric speed control means for the electric motor including a rotatable part moving angularly and periodically with the iirst section and including a second rotatable part moving continuously and angularly in timed relation with the second section, said control means causing the motor to move the second section at an average speed equal to the average speed of the first section.

6. In an Axminster loom provided with a conveyor system having two driven sections each movable to advance tube frames to a transfer station, pullover mechanism periodically moving part of one of said sections toward said station and determining the average speed at which said one section moves, variable speed driving means separate from the loom causing part of the other section to move continuously toward said station, :and means controlled jointly by the pullover mechanism :and fdr'iving means causing the latter to movesaid other section at .said average speed.

an v.Axrnin'ster loom tube 'frame conveyor system having one section thereof `driven vperiodically lby a -pui-llover shaft and h-aving .another section thereof driven by a variable speed :continuously running electric motor, a 'speed-con- 'trollerforthe motor including Ia rotary member driven 'bya force derived from the Ipullover shaft and a, second rotary member driven by Ia force derived from itl-re Vmotor cooperating -vvith -the -iirst 'member to l'cause 'the motor to run at varia- 'blespeedland move saidother section at an averlage speed-'equal to 'theaverage vspeed-atwhich the pullover 4sh-a'ftmove's saidfone section.

8. I-'n-San .Axminsterloom tube frame conveyor lsystem having fone section 'thereof :driven pe- 'iiodically -by a'pullover shaft and having vanother section thereof driven by a variable speed :continuously .running electric motor, a speed controller for the motor including a variable resistance jointly controlled by said sections and causing the motor to run at variable speed and move said other section at an average speed equal to the average speed at which the pullover shaft moves said one section.

9. In an Axminster loom tube frame conveyor system having one section thereof driven periodically by a pullover shaft and having another section thereof driven by a variable speed continuously running electric motor, a speed controller for the motor including a resistance member moved by the pullover shaft and a contact member moved by the motor cooperating with the resistance member to cause the motor to run at variable speed and move said other section at an average speed equal to the average speed at which the pullover shaft moves said one section.

10. In an Axminster loom having a tube frame conveying system formed with two tight sections, a pullover shaft moving one of said sections periodically, an electric variable speed motor separate from the loom continuously moving the other of said sections, and a unit for varying the speed of the motor including a resistance moving in timed relation with one of said sections and a contact for the resistance movable relatively thereto in timed relation with the other section, said unit causing the motor to run at Variable speed and move the section corresponding thereto at an average rate equal to the average rate of the section corresponding to the pullover shaft.

11. In an Axminster loom having a tube frame conveyor system including two tight sections movable relatively to each other, a sprocket wheel turned by one of said sections when the latter moves, pullover mechanism to move said one seotion periodically, a second sprocket wheel moved by the other section when the latter moves, an electric motor driving the second sprocket wheel, and speed control means for the motor including a resistance member moving with one of saidl sprocket wheels and a cont/actor moving with the other of the sprocket wheels and cooperating with the resistance member to cause the motor to drive said other section at an average rate equal to the average rate at which the pullover mechanism moves the iirst section.

12. In an Axminster loom having a tube frame conveyor system including two tight sections movable relatively to each other, a pullover shaft Periodically moving one of said sections, a second shaft operatively connected to the other section causing movement of the latter when said second shaft turns, an electric continuously running variable speed motor having driving relation with said second shaft, and control means for said motor including a resistance member moving With one of said sections and a contact member moving with the other section and cooperating with the resistance member to cause the motor to drive said second shaft at a rate which will cause the second section to move at an average rate equal to the average rate at,which the pullover shaft moves the first section.

13. In an Axminster loom provided with a tube frame conveyor system having two tight sections movable independently of each other and joined by two slack sections and wherein both tight sections are required to move substantially the same distance during an extended period of weaving, means operated by the loom periodically moving one of said tight sections and moving the latter said distance during said period of Weaving, a continuously running electric motor separate l2 from the loom operatively connected to the other tight section, and electric means jointly controlled by the tight sections causing the electric motor to move said other tight section said distance during said period of Weaving.

WALTER H. WAKEFIELD.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 

